The objective of this work is to determine the morphologic basis for the abnormalities noted with tests of early chronic obstructive pulmonary disease (COPD) by using excised human lungs from asymptomatic individuals with no known lung dieases. We will use postmortem physiology tests such as static pressure volume curves, single breath nitrogen tests, maximal expiratory flow volume curves using various gas mixtures, maximal mid-expiratory flow, FEV1 and FVC values, central and peripheral airway resistance. The physiologic data will be correlated with morphometric measurements of whole lung anatomy including airways and parenchyma. This study is designed to establish the anatomic basis for tests often used and believed to identify "small airway disease". The detailed functional and morphologic assessment of relatively young human lungs will add to our knowledge of the significance of mild or early lesions of airway and alveoli associated with chronic obstructive pulmonary disease.